feat: ConvertContentUseCase 구현

api/src/main/kotlin/com/few/api/domain/admin/document/dto/ConvertContentUseCaseIn.kt

@@ -0,0 +1,7 @@
+package com.few.api.domain.admin.document.dto
+
+import org.springframework.web.multipart.MultipartFile
+
+data class ConvertContentUseCaseIn(
+    val content: MultipartFile
+)

api/src/main/kotlin/com/few/api/domain/admin/document/dto/ConvertContentUseCaseOut.kt

@@ -0,0 +1,8 @@
+package com.few.api.domain.admin.document.dto
+
+import java.net.URL
+
+data class ConvertContentUseCaseOut(
+    val content: String,
+    val originDownLoadUrl: URL
+)

api/src/main/kotlin/com/few/api/domain/admin/document/usecase/ConvertContentUseCase.kt

@@ -0,0 +1,69 @@
+package com.few.api.domain.admin.document.usecase
+
+import com.few.api.domain.admin.document.dto.ConvertContentUseCaseIn
+import com.few.api.domain.admin.document.dto.ConvertContentUseCaseOut
+import com.few.api.domain.admin.document.service.GetUrlService
+import com.few.api.domain.admin.document.service.dto.GetUrlQuery
+
+import com.few.api.repo.dao.document.DocumentDao
+import com.few.api.repo.dao.document.command.InsertDocumentIfoCommand
+import com.few.storage.document.service.ConvertDocumentService
+import com.few.storage.document.service.PutDocumentService
+import org.springframework.stereotype.Component
+import org.springframework.transaction.annotation.Transactional
+import java.io.File
+import java.time.LocalDate
+import kotlin.random.Random
+
+@Component
+class ConvertContentUseCase(
+    private val documentDao: DocumentDao,
+    private val convertDocumentService: ConvertDocumentService,
+    private val putDocumentService: PutDocumentService,
+    private val getUrlService: GetUrlService
+) {
+    @Transactional
+    fun execute(useCaseIn: ConvertContentUseCaseIn): ConvertContentUseCaseOut {
+        val dateDir = LocalDate.now().toString()
+        val contentSource = useCaseIn.content
+
+        val documentSuffix = contentSource.originalFilename?.substringAfterLast(".") ?: "md"
+        val document = runCatching {
+            File.createTempFile("temp", ".$documentSuffix")
+        }.onSuccess {
+            contentSource.transferTo(it)
+        }.getOrThrow()
+        val documentName = "documents/$dateDir/${generateRandomName()}" + ".$documentSuffix"
+
+        val originDownloadUrl = putDocumentService.execute(documentName, document)?.let { res ->
+            val source = res.`object`
+            GetUrlQuery(source).let { query ->
+                getUrlService.execute(query)
+            }.let { url ->
+                InsertDocumentIfoCommand(
+                    path = documentName,
+                    url = url
+                ).let { command ->
+                    documentDao.insertDocumentIfo(command)
+                }
+                url
+            }
+        } ?: throw IllegalStateException("Failed to put document")
+
+        val html =
+            convertDocumentService.mdToHtml(document.readBytes().toString(Charsets.UTF_8))
+
+        return ConvertContentUseCaseOut(html.replace("\n", "<br>"), originDownloadUrl)
+    }
+
+    private fun generateRandomName(): String {
+        return randomString()
+    }
+
+    private fun randomString(): String {
+        val charPool: List<Char> = ('a'..'z') + ('A'..'Z') + ('0'..'9')
+        return (1..16)
+            .map { Random.nextInt(0, charPool.size).let { charPool[it] } }
+            .joinToString("")
+    }
+}